The compound (1α,2β,4β,5α,7β)-7-[(hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo[3.3.1.02,4]nonane-bromide, is known from European Patent Application EP 418 716A1 and has the following chemical structure:

The compound has valuable pharmacological properties and is known by the name tiotropium bromide (BA679). Tiotropium bromide is a highly effective anticholinergic and can therefore provide therapeutic benefit in the treatment of asthma or COPD (chronic obstructive pulmonary disease).
Tiotropium bromide is preferably administered by inhalation.
The aim of the present invention is to prepare HFA-metered-dose aerosols containing tiotropium bromide as the sole active ingredient in suspended form.